20th Force Glitch

The 20th Force Glitch is a glitch that allows one to change a borg into another borg, change a borg's color, change a borg's level, and change some other attributes of a borg. This gives players access to borgs that are usually inaccessible without cheat devices, such as G Black, Galactic Emperor, and pre-fused versions of combined borgs. It is believed that the glitch was found by a member of GF Wiki, a Japanese site. More information can be found in Voltrox747's guide and this forum topic.

All variations of the 20th Force Glitch involve moving borgs around in the box while the 20th force is selected. The cause of the glitch is unknown.

A Note About Freezing
The game can freeze at various points in this glitch. The cause of freezing is unknown, but it may be related to the game pulling data from places where there is no data. In certain cases, if the Warehouse and Box are full or close to full, the game is less likely to freeze. Therefore, it is recommended to fill up the Box and Warehouse. The fastest known way to do so is to play "The Oriental Battle" at Sunnyside Park repeatedly. However, when performing the identity-changing variation of the glitch, the reverse is sometimes true; the game is less likely to freeze if you do the glitch on a new file with a nearly empty Box and Warehouse. Experiment with both a new file and an existing file to see what works better for the particular purpose for which you're using the glitch.

GF Calculator
GF Calculator is a program that simplifies and automates calculations related to the 20th force glitch, especially the color-changing glitch and mutant borgs. See this page for details.

Changing a Borg's Identity
The simplest and most useful variation of the glitch allows one to change a borg into another borg. First, you must find the force sequence of the borg you want. A list of force sequences can be found in Voltrox747's guide. From there, the procedure is as follows (from Voltrox747's guide):


 * 1) Start a new file on a separate memory card. Although this is not required, it is recommended.
 * 2) Take G Red off the first force.
 * 3) Put the Normal Ninja on the forces in the force sequence selected earlier. For example, if the force sequence is "2, 4, 6, 10, 11", you would put the Normal Ninja on forces 2, 4, 6, 10, and 11. The force sequence determines the borg that you will get. A list of force sequences can be found in Voltrox747's guide. It is believed that the slot in which you place the Normal Ninja has no effect. For example, you could place the Normal Ninja on the first slot in a force, the second slot, or any other slot.
 * 4) Scroll to the 20th force.
 * 5) Place G Red in the 23rd slot.
 * 6) Place Revolver Gunman in the 15th slot.
 * 7) Move the cursor to any empty cell in the box and press A. The game should make a sound as if you picked up a borg.
 * 8) Move the cursor on top of Normal Ninja and Press A. The 20th force should fill up with borgs.
 * 9) Press B to release the Normal Ninja.
 * 10) Pick up the borg in slot 24.
 * 11) Move the borg to slot 15, then press B to release the borg that was formerly in slot 15.
 * 12) Move the cursor to any empty cell in the box (other than the third cell, i.e. the cell two spaces to the right of the upper left corner) and press A. Once again, the game should make a sound as if you picked up a borg.
 * 13) Move the cursor to the second cell in the box (i.e. the one just to the right of the upper left corner).
 * 14) Press A. The borg in the second slot should change to one that corresponds to the force sequence you used.
 * 15) Press B to release the borg you just picked up.
 * 16) Delete every force.

The Normal Ninja is now something else, depending on the force sequence used. As mentioned above, though, the game can freeze at multiple places in this procedure. If you make it through all the steps above and can check the borg's stat screen without freezing the game, it's likely that the borg can be used in battle.

Other borgs can be used in place of G Red, Normal Ninja, and Revolver Gunman. The new borg will retain certain attributes of the borg used in place of Normal Ninja, such as level, color, and experience.

Video Demonstration

Changing a Borg's Color and Level
This variation of the glitch allows you to change a borg's color and level. However, it is highly prone to freezing the game. See the section above for an important tip on preventing freezing. Before performing this glitch, you must determine the code number corresponding to the level and color you want. This table gives the color and level corresponding to each code number:

So, if you know what color and level you want, you can use the table to find the corresponding code number. See the example below for a step-by-step breakdown. Or use the GF Calculator.

The effects of code numbers above 1535 are unknown. Levels outside the range of 1-10 can result in mutant borgs. The switches that occur in the middle of a color's code number range (e.g. 0-255 for normal) are believed to be caused by the use of 8-bit signed integers.

Once you pick the code number, you must convert it to a force sequence; see the section below for instructions on doing so. From there, the procedure is as follows:


 * 1) Delete all forces.
 * 2) Call the borg whose level/color you want to change the "target borg." Put the target borg on the forces in the force sequence calculated earlier. For example, if the force sequence is "1, 4, 10", put the borg on forces 1, 4, and 10.
 * 3) Scroll to the 20th force.
 * 4) Put another borg on the 23rd slot.
 * 5) Put yet another borg on the 15th slot.
 * 6) Move the cursor to any empty cell in the box and press A. The game should make a sound as if you picked up a borg.
 * 7) Move the cursor on top of the target borg and press A. The 20th force should fill up with borgs.
 * 8) Press B to release the borg you're holding.
 * 9) Pick up the borg in slot 24.
 * 10) Move it to slot 16, then press B to release the borg that was formerly in slot 16.
 * 11) Move the cursor to any empty cell (other than the cells occupied by the borgs in slots 23 and 15) and press A. Once again, the game should make a sound as if you picked up a borg.
 * 12) Move the cursor on top of the target borg.
 * 13) Press A. The color and level of the target borg should change to those selected earlier.
 * 14) Press B to release the borg you just picked up.
 * 15) Delete every force.

The borg's level and color are now changed.

Video Demonstration

Force Sequences
The force sequence used in the glitch determines the outcome of the glitch. A force sequence is a list of numbers from 1 to 20, arranged from least to greatest. Each number can only appear once in the list. For example, "1, 2, 3" is a force sequence; "1, 1, 2" is not. The sequence can be empty, meaning that it contains no numbers.

A force sequence can be identified with a single code number as follows. Suppose the force sequence is $$a_1, a_2, ..., a_n$$. Write $$a_n$$ zeroes. Change the $$a_1$$th digit from the right into a one, then change the $$a_2$$th digit from the right into a one, and so on until you change the $$a_n$$th digit from the right into a one. The result is the code number (in binary) corresponding to the force sequence. This number can be converted to decimal with a converter such as this one. Another procedure for obtaining the code number is as follows: if the force sequence is $$a_1, a_2, ..., a_n$$, then the code number is $$\sum_{i=1}^n{2^{a_i - 1}}$$. If the force sequence is empty, the code number is 0.

Given the code number corresponding to a force sequence, you can determine the sequence. First, convert the code number to binary; this can be accomplished with a converter such as this one. Then, counting from the right, list the positions of all the ones. For example, if the number is 10010 in binary, then the force sequence is "2, 5". If the code number is 0, the force sequence is empty.

All the calculations described here can be performed by the GF Calculator.

Example
Let's say we want a level 10 gold borg. First, we must determine the code number for gold level 10. Look at the table above. Since 10 is a positive number, the code number will be in the range 512-639, so the level will be 511 less than the code number. Thus, the code number is 521 (which is 10 + 511). Now we must convert this code number to a force sequence. Using this calculator, we find that 521 is 1000001001 in binary. From right to left, we list the positions of the ones: 1, 4, 10. Now follow the directions in the level changing section.

Mutant Borgs
Certain pieces of information called level attributes are determined by a borg's level:


 * How much HP a borg has
 * How much of each type of ammo a borg can hold
 * How much of each type of ammo a borg starts with
 * How quickly each type of ammo refills
 * Whether each type of ammo refills gradually or all at once
 * Some other data related to ammo

Each color of a borg has 20 levels associated with it, even though only 10 are normally used. If a borg's level is changed to something other than those 20, the borg will gain the level attributes of another borg. The borg whose attributes are replaced is called the recipient; the borg whose attributes are used in their place is called the donor. The resulting borg is called the mutant. The game has an internal list of borgs that determines the identity of the donor (i.e. which borg it is) based on the identity, color, and level of the recipient. It is believed that this list is in the same order as the one in Voltrox747's guide. This table allows you to determine the identity of the donor:

For example, let's say you have a level 41 silver Shadow Girl. The table above tells us that this level and color will result in an ID shift of +2. Now look at the list in Voltrox747's guide. The borg 2 places after Shadow Girl is Cyber Girl Hyper, so Cyber Girl Hyper is the donor of level attributes. Shadow Girl is the recipient. The mutant moves, attacks, and looks like silver Shadow Girl, but has the level attributes of Cyber Girl Hyper.

The level of the donor can be predicted as follows. First, you need to know the "level bonus" corresponding to the color of the recipient. The "level bonuses" are as follows:


 * Normal: 0
 * Alternate: 0
 * Clear: -2
 * Silver: 4
 * Gold: 6
 * Black: 2

Once you have the level bonus, follow this procedure:


 * 1) Add the level of the recipient and the level bonus corresponding to the color of the recipient.
 * 2) Take the result mod 20; this means that you divide the number by 20 and use the remainder as your result. For example, 83 divided by 20 is 4 remainder 3, so 83 mod 20 is 3. For negative numbers, use a negative remainder. For example, -45 divided by 20 is -2 remainder -5.
 * 3) If the result is less than -1, add 20. Otherwise, don't change it.
 * 4) If the result is greater than 18, subtract 20. Otherwise, don't change it.

The result is the "normal-equivalent" level of the donor, meaning that the donor has the level attributes corresponding to a normal-colored borg with that level. For example, consider level 41 silver Shadow Girl. Following the process above, we add the silver level bonus of 4 to get 45. Then we take 45 mod 20 and get 5. Since 5 is not greater than 18, we don't subtract 20. This tells us that the normal-equivalent level of the donor (Cyber Girl Hyper) is 5. From the information on Cyber Girl Hyper's page, we would expect the mutant Shadow Girl to have 320 HP. This is indeed the case.

Note that the GF Calculator can perform all the calculations described above automatically.

The above process does not always correctly predict the level attributes of a borg. For unknown reasons, there are levels where a borg's HP is the same as it is at the previous level. For example, level 122 normal Shadow Girl and level 123 normal Shadow Girl both have 310 HP. Experimentation is needed to confirm the results of a mutation. And as always, the game may freeze; see the section above for an important tip on preventing freezing.

In battle, if the donor has a type of ammo that the recipient does not, then the mutant will have that type of ammo, but they won't be able to use it. For example, if you give G Red some X ammo, pressing X will still cause him to do a G Crash. The reverse situation has more possibilities. If the donor lacks a type of ammo that the recipient has, then several things can happen:


 * The mutant cannot use that type of ammo.
 * The mutant can fire a single shot of that type of ammo in each battle.
 * The mutant has an infinite amount of that type of ammo.

Pulling Data From Outside the Level Attributes List
If a mutant borg's ID shift takes them outside the level attributes list (believed to be the same as the list in Voltrox747's guide), then their level attributes are pulled from unknown sources. This can have strange effects. Here are some examples:


 * Normal Ninja is at the beginning of the level attributes list. A level -127 Normal Ninja has some huge amount of HP. It displays as 9999 in battle, but the Normal Ninja can take a lot of damage before dropping below 9999. He also has a huge amount of B ammo that displays as 999, but takes about five minutes to fill up. He has no X ammo. Video (#6)
 * Level -124 Normal Ninja has 0 HP and infinite ammo. If he is the last borg in a force when he dies, the battle keeps going. Video (#11)
 * Level -126 Normal Ninja has 0 HP and no ammo.
 * Death Eye is near the end of the level attributes list. A level 40 Death Eye has a huge amount of HP like level -127 Normal Ninja. He has no ammo, but for some reason it displays as 000 instead of just 0. Video (#15)
 * Level 52 Death Eye has 24 HP, 12 B ammo, and 29 X ammo. The B ammo doesn't refill. Video (#17)
 * Level 53 Death Eye has 117 HP, 182 B ammo, and 181 X ammo. The B ammo doesn't refill. Video (#18)

Oddities with Negative ID Shifts
If a mutant's ID shift is negative, sometimes the level of the borg (and possibly the ID shift) will change when the borg gains experience or when it is transferred to another memory card. The conditions under which this occurs are unclear.